Add symbolic links to explorer for bx and sx.
Add images.
Update doc.
Add command aliases.
Remove unused boost component from build.
Help command return okay when not parameterized.
Support test from non-default folder installation.
Merge pull request #32 from evoskuil/develop

Update doc, add bx & sx command aliases, tweak builds.
Merge pull request #33 from libbitcoin/develop

Merge develop.